Digital signal processing
Upcoming SlideShare
Loading in...5
×
 

Like this? Share it with your network

Share

Digital signal processing

on

  • 392 views

 

Statistics

Views

Total Views
392
Views on SlideShare
388
Embed Views
4

Actions

Likes
0
Downloads
17
Comments
0

1 Embed 4

http://www.slideee.com 4

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Digital signal processing Presentation Transcript

  • 1. Technology Training that Workswww.idc-online.com/slideshare Digital Signal Processing
  • 2. Technology Training that Workswww.idc-online.com/slideshare Welcome to this webinar with Dr Steve Mackay There are at least 3 ways to interact with your presenter today. 1. Use the Text tab, near bottom left of your screen. Type the message in the space next to the “Send” button, then enter or click Send. (Ensure “All” is selected in the drop-down menu under the typing area) 2. Use the Emoticons selection in the text window – choose an emoticon then click send or enter. 3. Talk! Click the Push To Talk button. The button will change to yellow when you are queued, then green to show that your microphone is live. Remember to click it again when you have spoken This 45 minute session will commence shortly! RH
  • 3. Technology Training that Workswww.idc-online.com/slideshare Steve Mackay • Dean of Engineering • Worked for 30 years in Industrial Automation • 30 years experience in mining, oil and gas, electrical and manufacturing industries
  • 4. Technology Training that Workswww.idc-online.com/slideshare DSP • Digital - finite set of distinct values. • Analog - continuous range of values. • DSP Processing means processing of signals which are: – Discrete in time. – Discrete in amplitude.
  • 5. Technology Training that Workswww.idc-online.com/slideshare Two sources of discrete signals •Ones that are discrete in nature. •Sampled version of a continuous-time signal.
  • 6. Technology Training that Workswww.idc-online.com/slideshare Why Process Signals Digitally? • The signals are inherently discrete in nature. • Consistency -- compared with analog methods.
  • 7. Technology Training that Workswww.idc-online.com/slideshare Definition of Terms • Signals: A quantity that can be measured over time. • Frequency: A signal is said to have a frequency of 50 or 60 Hz. • Spectrum: Some signals have a combination of frequencies.
  • 8. Technology Training that Workswww.idc-online.com/slideshare • Low Pass Filter: This lets through the low pass component. • Bandpass Filter: Only a range of frequencies is passed through intact. • High-pass Filter: Allows frequencies above a certain frequency to pass through intact.
  • 9. Technology Training that Workswww.idc-online.com/slideshare Some Application Areas • Speech and Audio Processing. – Coding. – Synthesis. – Recognition.
  • 10. Technology Training that Workswww.idc-online.com/slideshare Companding Process
  • 11. Technology Training that Workswww.idc-online.com/slideshare Adaptive Differential Pulse Code Modulator
  • 12. Technology Training that Workswww.idc-online.com/slideshare Linear Predictive Coding
  • 13. Technology Training that Workswww.idc-online.com/slideshare Image and Video Processing • Image Enhancement. • Image Restoration. • Image Compression and Coding.
  • 14. Technology Training that Workswww.idc-online.com/slideshare Adaptive Filtering • Noise Cancellation. • Echo Cancellation. • Channel Equalisation.
  • 15. Technology Training that Workswww.idc-online.com/slideshare Adaptive Noise Cancellation System
  • 16. Technology Training that Workswww.idc-online.com/slideshare Adaptive Echo Cancellation System
  • 17. Technology Training that Workswww.idc-online.com/slideshare Adaptive Equalizer in Training Mode
  • 18. Technology Training that Workswww.idc-online.com/slideshare Control Applications • Controlling closed-loop feedback systems. • Controller implements algebraic algorithms such as filters and compensators.
  • 19. Technology Training that Workswww.idc-online.com/slideshare Digital Closed Loop Control System
  • 20. Technology Training that Workswww.idc-online.com/slideshare Sensor or Antenna Array Processing • Spatially distributed sensors are used for receiving signals from some sources. • Coherent summing of outputs from these sensors referred to as beamforming. • One can “listen” preferentially to wavefronts originating from one direction over another.
  • 21. Technology Training that Workswww.idc-online.com/slideshare Digital Communication • New Architecture called software radio. • Use of wideband A/D and D/A converters to convert RF or IF signals directly.
  • 22. Technology Training that Workswww.idc-online.com/slideshare Software Radio Architecture
  • 23. Technology Training that Workswww.idc-online.com/slideshare Converting Analog to Digital Signals and Vice Versa
  • 24. Technology Training that Workswww.idc-online.com/slideshare A Typical DSP System • Three stages: – The analog signal is digitized. This involves • sampling • quantization – Digital signal processed by DSP algorithms. – Outputs converted back into analog signals.
  • 25. Technology Training that Workswww.idc-online.com/slideshare Analog-Digital-Analog
  • 26. Technology Training that Workswww.idc-online.com/slideshare Temperature Variation in a Day
  • 27. Technology Training that Workswww.idc-online.com/slideshare The Sampling Process
  • 28. Technology Training that Workswww.idc-online.com/slideshare Uniform Sampling Theorem • If a continuous time signal contains no frequency components higher than W Hz, then it can be completely determined by uniform samples taken at a rate fs samples per second where • or, in terms of the sampling period f Ws ≥ 2 T W ≤ 1 2
  • 29. Technology Training that Workswww.idc-online.com/slideshare Two Bandlimited Spectra
  • 30. Technology Training that Workswww.idc-online.com/slideshare Replication of Spectrum through Sampling
  • 31. Technology Training that Workswww.idc-online.com/slideshare Replicated Spectrum
  • 32. Technology Training that Workswww.idc-online.com/slideshare Aliasing
  • 33. Technology Training that Workswww.idc-online.com/slideshare Sampling at Different Rates
  • 34. Technology Training that Workswww.idc-online.com/slideshare Effect of Aliasing
  • 35. Technology Training that Workswww.idc-online.com/slideshare Anti-aliasing Filters • Process the signal before it is sampled so they are always analog filters. • Usually low-pass filters unless bandpass sampling techniques are used.
  • 36. Technology Training that Workswww.idc-online.com/slideshare Analog-to-Digital Conversion with Anti-alias Filtering
  • 37. Technology Training that Workswww.idc-online.com/slideshare Implications of Non-ideal Anti-alias Filters • Sample at higher than Nyquist rate. • If sampling rate cannot be changed, then a filter with sharper cut-off (implying a higher order filter) has to be used.
  • 38. Technology Training that Workswww.idc-online.com/slideshare Limits on Sampling Rates • Practical choice of sampling rate is determined by two factors: – Sampling theorem places lower bound on the allowed values of sampling frequency. – Economics of hardware imposes upper bound on sampling frequency.
  • 39. Technology Training that Workswww.idc-online.com/slideshare Thank You For Your Interest If you are interested in further training, please visit: http://www.idc-online.com/slideshare